<div class="saturation" 
    :style="{background: bgColor}"
    v-el:container
    @mousedown="handleMouseDown">
    <div class="white"></div>
    <div class="black"></div>
    <div class="pointer" :style="{top: pointerTop, left: pointerLeft}">
      <slot><div class="circle"></div></slot>
    </div>
</div>